Biosimilar of Remicade Holds Up at 2 Years

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Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

SAN DIEGO -- A monoclonal antibody that's "biosimilar" to infliximab (Remicade) in rheumatoid arthritis showed safety and efficacy profiles that were comparable with the now off-patent original biologic, according to studies presented here.

After 2 years of treatment, rates of 20% response according to the American College of Rheumatology criteria (ACR20) were 72.2% among patients who had received the biosimilar, CT-P13, throughout and 71.8% for patients who had been given infliximab for the first year and then were switched to the biosimilar for the subsequent year, according to lead investigator Dae-Hyun Yoo, MD, of Hanyang University in Seoul, South Korea.

"The safety signals were what we expected and didn't seem to be meaningfully different," he told MedPage Today.

At 2 years, the proportion of patients with one or more treatment-emergent adverse events was similar in the group that had consistently received CT-P13 and those who switched from infliximab (53.5% versus 53.8%), according to the investigators.

As with the ACR20 response rate, similar percentages achieved ACR50 and 70 responses at 2 years -- 48.3% and 24.5% for the maintenance CT-P13 group and 51.4% and 26.1% in the switched group.

Changes in the Disease Activity Score in 28 joints (DAS28) also were similar, at a -2.4 point change at both years 1 and 2 for the maintenance group and -2.4 and -2.5 in the switched group.

About 50% of patients in both groups developed anti-drug antibodies by 2 years.

"We have no idea what the impact of these antibodies is on safety or efficacy. That isn't clear from the data," Matteson said. "This will be important because the effects might not be seen for years, and the TNF inhibitors like infliximab can lose efficacy over time, probably related in part to anti-drug antibodies."

The European Medicines Agency recently recommended that CT-P13 be approved, and it's probable that the U.S. will follow suit, according to Matteson.

"I think that if the efficacy and safety data and confidence in the manufacturing process hold up, the likelihood of approval is very high. In fact I think it's inevitable that it will happen," Matteson said.

The biosimilar also is being evaluated in conditions other than rheumatoid arthritis, such as seronegative arthritis, he noted.

Biosimilars also are being developed for etanercept and rituximab, and are moving along rapidly.

"But the FDA needs to address the manufacturing processes. Also, we don't yet know what the long-term effects will be, and whether the concerns about infection and malignancy are different than for the original monoclonal antibody," he concluded.

The study was sponsored by Celltrion. Yoo and several co-investigators disclosed relationships with the company.